World History
Dissolved Empires
Empires that either don't have a convenient modern equivalent, don't have a widely recognized successor state, or are so ancient that successor states aren't relevant. The USSR actually does fall into those descriptions but it's rather insufficient to treat it as just a chapter of Russian history.
Empires are distinguished from international organizations by the number of states with effective agency. The EU is multi-polar, while the USSR was not.
Dissolved States
States that either don't have a convenient modern equivalent, don't have a widely recognized successor state, or are so ancient that successor states aren't relevant. Yugoslavia is a bit iffy but I include it anyway.
Excludes empires.
Historic Regions
Regions that have historic context, but not a historic state.
International Wars
Anglo-Spanish War and the Treaty of Seville
- Italian Wars of Independence
Seven Years War and the Treaty of Paris
Thirty Years' War and the Peace of Westphalia
War of Austrian Succession and the Treaty of Aix-la-Chapelle
War of Spanish Succession and the Treaty of Utrecht
War of the Quadruple Alliance and the Treaty of the Hague
International Organizations, Treaties, and Laws
Anti-Comintern Pact
Molotov-Ribbentrop Pact
Tripartite Pact